Switch



' July 19, 1960 B. w. sEwELl. 2,945,926

SWITCH Filed Aug. 4. 1945 2 Sheets-Sheet 1 ma:v

. INVENTOR BEN WSEWELL ATTORNEY July 19, 1960 B, w. sEwELL 2,945,926

' SWITCH Filed Aug. 4, 1945 2 Sheets-Sheet 2 INVENTOR BEN MSEWELL /IQ Q/Qz...

ATTORNEY UnitedStates. Patent' SWITCH Ben W. Sewell, Tulsa, Okla., assignor to the United States of America as Navy piled Aug. `4, 194s, ser. No. 608,955 l "z yolaims. (creen-6mm represented bythe Secretary of the ntilcountermining devices of various forms, usually in t the form of a switch, have previously been proposed for the purpose of automatically deactivating or breaking'the operative connection between the mine detonating charge and its initiating means, in response to a nearby underwater explosion, and then reestablishing the operative connection when the effects of the explosion have ceased. Generally, the anti-countermining device is operated by the action of an underwater shock wave on a movable elementof the device which is thus moved to a deactivating position against a biasing means, the latter acting to return the element to its normal position upon cessation of the shock eifgect. Prior devices of this character have, not been entirely satisfactory for various reasons, among which are their Vlack of the desired degree of sensitivity, their complicated structure, their tendency to interfere with the normal operation of the mine, and the fact that they` are notY always positive in action. Y

One object ofthe present invention, therefore, resides in the provision of an anti-countermining device which overcomes these'objections to prior devices-of this type.

Another object of the invention is to provide ananticountermining device which is positive in action and' yet has the desired degree of sensitivity, by reason'of its'inclusion vof a restrained actuating ball operable by ananvil in response to an underwater shock wave. A.

`. lAnotherobjec't is to' provide a device of the character described having selector means operable readily to lock the device in its deactivating position or to release the deviior normalpratioa, as desired t her object is to provide a device of the character described in which the operating 'train to the explosive detonator of a mine, or the like, may be broken by a spring biased contact directly associated with the actuating ball.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

Fig. 1 is a longitudinal sectional view of a war head showing the location of the new anti-countermining device in the detonator or exploder;

Fig. 2 is a vertical sectional View of one form of the new anti-countermining device, on a much longer scale than Fig. l;

Peterrted July 19,` 1.960V

Fig. 3 is a horizontal sectional view in plane 3-3 of Fig. 2;

Fig. 4 is a fragmentary detail sectional view in plane 4-4 of Fig. 2; Fig. 5 is a bottom view of part of the devicev shown in Fig. 2, and

Fig. 6 is an exploded perspective view of part of the body and the selector means of the device.

Referring to Fig. l there is shown a torpedo war head 10 comprising the usual casing or shell 11 containing a high explosive charge 12 cast around an exploder 13. As the exploder 13 perse forms no part of the present invention, it is not described in detail, it being understood that it may be of the type which operates on impact or by proximity'of the target. An operatingconnection 13a leads from the exploder to a generally cup-shaped housing 14 in the explosive charge 12. The housing 14 is secured in any suitable manner to the shell 11 with the open end of the cup disposed over an opening 15 in the shell. Y The anti-countermining device of the present invention comprises a cup-shaped steel body 17 having at its closed end a peripheral flange 17a;V A plurality of holes` are spaced around Vthe ange 17u and arev counterbored, .as shown at 18,'to receive screws 19 for securing the body to the housing 14. The body 17 ,tits into the housing 14 with the flange 17a resting against a similar flange ,on housing 14, the screws 19 being tightened to compress al gasket 20 between the anges and thereby providea water-tight seal. With the body 17 thus mounted in the war head, the outer face 17b of the body is in direct contact with the surrounding water. o' The body 17 hasA a main chamber22 and a central subchamber23 extending from the main chamber toward the, outer' f ace 17b but terminating short'of the latter face, At its outer end, the sub-chamberV 23 has a central boss, 24 which supports an anvil'25 in theV sub-chamber. VA cage 26 is threaded into the sub-chamber 23 andis screwed tightly against the vanvil to hold the latter firmly seated on -theboss '24.V The cage 26 contains ,a hardened steel ball -27 which tits in the cage with a slight clearance and is capable of limited longitudinal movement therein. A frame 30 made ofinsulating material extends transv erselylacross the nia-in chamber 22 intermediate itsend's and has 'hollow cylindrical end'extensions 31 and 32,

Y r the extension '31 resting upon a shoulder 22a. iAfT- normally spaced from a contact screw'` 36 which is ad-i shaped spring arm 33 extends transversely across the* space within thethollowframe extension 31, the head of the lspring'arm being secured to frame 30 by screws L34. At its free end, V.the arm 33carries a movable contactg35 justable inva bushing 37 in frame Y30.l `A downwardlyv extending stud 38 is secured tothe spring arm 33 intermediate itsj ends' and .normally engagestheadjacent surface of .bau E21, M,the stu-d beingidisposed radiallymth respect to the ball.

The open inner end of body 17 is counterbored to receive'a washer 40 and a closure member 41. The closure member 41 is secured in the counterbore with a water tight seal, as shown at 42, in engagement with the outer face of the washer. Wires 34a and 36a are connected, respectively, to one of the screws 34 and the contact screw 36, the wires being included in a cable 43 extending outwardly through central openings in washer 40 and closure member 41. The closure member 41 has a central chamber which is tapered at its lower end, as shown at 44, and receives packing 4S disposed around the cable 43. A washer 46 is seated on top of the packing and has bevelled inner edges 46a. The parts within the closure member 41 are retained under pressure by a cap 47 threaded over the upper end of the closure member.

It will be evident that when the cap 47 is tightened d'own against washer 46, the packing 45, due to the surfaces 46a and 44, is forced inwardly against the cable to form a water-tight seal. Y

' A shaft 50 is rotatable in body'17 adjacent the subchambert23. OnV its inner end, the shaft has a radial arm '51 disposed within the hollow frame` extension 31, the latter being cutaway at 31a to provide a clearance for the arm. At its free end, the arm 51 has an upturned portion terminating in a cam surface 52. The shaft 50 is urged inwardly by a compression spring 53 which retains a screw head 54 on the shaft against a seat in the body. The head 54 extends outwardly into a recess 55 in the body, the recess being closed by a plug56 screwed into the outer face 17b against a gasket 57.

In the use of the new device, the wires 34a, 36a are connected to the exploder 13 in such a manner that the latter is deactivated or rendered inoperative whenever the wires are shorted by closing of switch 35,-36. If the exploder is operated electrically, the wires 34a, 36a may be connected into the exploder circuit so that the energizing source is shunted from the exploder whenever switch 35-36 is closed.

'In operation, an underwater shock wave impinging upon the outer face 17b is transmitted through the body 17 and boss 24 to the anvil 2S, the part of the body under the boss acting as a diaphragm. As a result, the ball 27 is bounced oi the anvil and operates through stud 38 to close the switch 155-36, thereby deactivating the exploder. When the ball returns to the anvil (under the action of gravity, as shown) a subsequent shock wave transmitted to the anvil, or the bouncing action of the ball, or both, will cause a repetition of the operation described, so that the switch will flutter between its open and closed positions. This fluttering action of the switch is suicient to prevent operation of the exploder, because of the inherent time lag in the exploder operating means. When the effects of the underwater explosion or other disturbance have subsided, so that shock waves are no longer transmitted to the anvil 25, the ball comes to rest in its normal position on the anvil and the arm 33 returns to its normal open-switch position, and thereupon theexploder 13 may be actuated in the usual manner.

If desired, the anti-countermining device may be used as a. safety device when the torpedo is not in use, by operatingy the selector shaft 50. To this end, the plug 56 is4 removed, and a screw driver is inserted in the screw head 54 for rotating the shaft S0. Rotation of shaft S0 causes the cam surface 52 on arm 51 tomove under the spring arm 33,. forcing contact 35` into engagement with fixed contact 36 and thereby short circuiting the operating means for exploder 13. The torpedo is thus rendered safe until selector shaft 50 is rotated back to its initial position to release switch arm 33 from the locking. cam 52 and reopen switch 35-36.

By reason of the ball, and anvil members 27, 25, the new anti-countermining device has greatly improved operating characteristics, is positive in operation, and can be provided with a shock sensitivity commensurate with that of the exploder. Due to the mass of the ball 27, the device is resistant to operation under the influence of spurious or minor shock effects which would be insuflicient to actuate the exploder. The tension in the spring arm .33,acts to maintain the ball on its anvil 25. It will beievident that the sensitivity of the device may be regulated by adjusting the contact screw 36 in the bushing 37 prior to closing the inner end of body 17 with the closure member 41.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

I claim:

1. In a switch comprising a spring having an electrical contact thereon, an adjustable relatively stationary contact coacting therewith, and normally spaced therefrom, to control a circuit, an abutment carried by said spring, a spherical member in mechanical contact with said abutment, an anvil having a surface tangential to said member at the other end of the diameter of said member terminating at the abutment, the member being free to rotate in any direction, and means for transmitting mechanical impulses to said anvil; in combination, means for shortcircuiting said switch contacts at will, and means operable to move said short-circuiting means.

2. In an anti-countermining device having a hollow body with an outer face, a normally open electrical operating circuit and including a switch across said circuit, an anvil, means for transmitting switch-actuating impulses thereto, a sphere resting on said. anvil, a spring', an electrical contact carried thereby, a mechanical abutment also carried by said spring and having its end touching the sphere, means constraining said sphere to maintain such position that the contact member and the anvil will always touch, said sphere being free to rotate in every sense, a second electrical contact, and means for adjustably supporting said second electrical contact adjacent the rst named contact; in combination, a locking cam in said body movable selectively to lock said spring together with said electrical contact in its exploderdeactivating position and to release said spring and its electrical contact, and. selector means in said body and operable through said outer face to move said cam.

References Cited in the le of this patent UNITED STATES PATENTS 1,310,568 Heap et al. July 22, 1919 r1,448,976 Palmer Mar. 20, 1923 1,626,794 Dieter May 3, 1927 2,153,114 Boerlage Apr. 4, 1939 2,400,549 Glennon et al. May 21, 1946 2,415,086 Detwiler Feb. 4, 1947 FOREIGN PATENTS 786,910 France June 24, 1935 

